In fact the important thing is not the number of brain cells we have, but how well they connect with each other, and the more a brain is fed and stimulated, the stronger and more complex these connections grow. So, the more a child learns and thinks, the more powerful and effective her brain becomes, while a child who gets little mental stimulation will find learning anything an uphill struggle.

We also know that mood, behavior and the 'stories' we tell ourselves about what we can and can't do all have a direct effect on how well we learn. If we can help our children get those right, we will set them flying along the path to success.

How do we know this?
Our growing understanding of all this comes partly from new technology, which allows us to watch the nerve fibres in people's brains making connections as they think, and partly from an ever-increasing awareness that intelligence is so much more diffuse and multi-faceted than we once believed.

Intelligence floods every molecule of our being and is impossible to confine to that narrow band of learning we so love to test in school exams. And how we define it also depends on circumstances. To a bat, piloting itself around by ultrasonic sounds, human beings are blundering primitives in a world they completely fail to 'see', while to a Kalahari bushman, who has to know how to find water in the desert to survive, even a visiting Einstein would seem dumb.

And even within our own small world of Western culture, definitions of intelligence can be wildly off the mark. Is the child who comes top of the class necessarily the smartest kid in the room? Apparently not. Psychologists in the US have found that the best predictor of success in later life is not what children know, but how well developed their social skills are.

The eight, nine, ten intelligences . . . ?
Ever since the 1980s when American psychologist Howard Gardner revolutionized our perception of intelligence by saying it came in all sorts of guises, our flunking about brainpower widened. Gardner came up with eight intelligences. Others have since added more. It probably doesn't matter exactly how many, since these are simply ways of chopping a very complex whole into parts in order to help us understand the big picture. One list of intelligences might read:

linguistic - you like words, stories, languages
logical-mathematical - you like numbers, abstract thinking, problem-solving
visual-spatial - you like pictures, color, shapes
physical - you like to use your body and hands
musical - you like pitch, sounds, rhythms
emotional - you enjoy thinking, reflecting and analyzing yourself
social - you like mixing, communicating, negotiating
intuitive - you like feelings, values, self-knowledge.

As parents, we know at once that these ring true. We all have children who are good at this, and not so hot at that, and we've probably all had moments when we've felt exasperated that our children's schools seem quite unable to grasp the whole, miraculous picture of their abilities and talents. In fact the common grumble of us parents that our children are not being fully stretched at school may well be because we have this close-up, visceral knowledge of our children's many interwoven abilities, and see immediately when chunks of these are going unnoticed or unaddressed, while schools, which are judged on how well they deliver the national curriculum, have to focus mainly on the verbal and mathematical skills that matter most to them.